Conventionally, cholesterol receives attention as a lipid that causes congestive heart failure, arteriosclerosis, dementia, and the like, and arteriosclerosis, for example, has been believed to develop due to cholesterol accumulation in the vascular subendothelium. As a means for preventing or treating such diseases, various pharmaceutical formulations including statin drugs that target cholesterol have been developed (Patent Literature 1 to 3, for example).
It has become clear that reduction of cholesterol by such formulations decreased the incidence of cardiovascular disease by about 30%, for example, but the other 70% of the patients were not controlled, indicating that the effect is inadequate.
When used for diabetic patients, such cholesterol-lowering drugs showed effects on only about 20% of the patients in terms of treating diabetic cardiovascular complications including cardiovascular disease, indicating that such drugs are not effective enough.
Risk factors for arteriosclerosis are thought to include hypercholesterolemia, smoking, hypertension, diabetes, and obesity, and these risk factors are believed to promote the progress of arteriosclerosis. Therefore, managing or reducing such risk factors is generally thought to be effective in preventing or treating arteriosclerosis.
Aggressive management of such risk factors, however, has not yet successfully inhibited the development of cardiovascular complications in diabetic patients. Nor has surgical treatment (coronary angioplasty and bypass surgery, for example), which is one of the therapies for arteriosclerosis, been effective enough in treating diabetic arteriosclerosis. Therefore, development of a drug that is highly effective in treating diabetic cardiovascular complications in diabetic patients has been desired.